It has proven desirable to provide earth-loading buckets with relatively wide entrances, as defined by the front edge and side walls of said buckets, in order to allow the greatest possible amount of material to be loaded into the bucket as the front edge of the bucket loosens and lifts said material as the bucket travels over the terrain to be cleared.
However, relatively wide buckets are difficult to unload when the width of the receptacle is insufficient to accommodate all the falling debris and earth material. This may occur even though the width of the receptacle is greater than the width of the bucket as material falling from a bucket has the tendency to spread outwardly from the sides of the bucket, resulting in loss of material over the front or rear of the receptacle. This is especially inconvenient when the receptacle is a truck without a protective cover for the operator's station at the front of the vehicle.
It has been determined that if the ratio of the width of the receptacle to the width of the bucket is less than about 1.4 to 1, the bucket must be positioned substantially centrally of the receptacle to avoid spillage of material over the sides of the receptacle when emptying the bucket. This is a disadvantage, as centering of a loader with respect to the receptacle may be impractical due to space and time limitations.
When the length of the truck bed (measured from the operator's station to the rear of the bed), or other receptacle, is only slightly greater than the width of the bucket opening, spillage problems may occur even if the bucket is centered with respect to the receptacle. This situation arises in cases where relatively short dump trucks are utilized in material-moving operations.